Does different activation between the medial and the lateral gastrocnemius during walking translate into different fascicle behavior? - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Experimental Biology Année : 2021

Does different activation between the medial and the lateral gastrocnemius during walking translate into different fascicle behavior?

Résumé

The functional difference between the medial gastrocnemius (MG) and lateral gastrocnemius (LG) during walking in humans has not yet been fully established. Although evidence highlights that the MG is activated more than the LG, the link with potential differences in mechanical behavior between these muscles remains unknown. In this study, we aimed to determine whether differences in activation between the MG and LG translate into different fascicle behavior during walking. Fifteen participants walked at their preferred speed under two conditions: 0% and 10% incline treadmill grade. We used surface electromyography and B-mode ultrasound to estimate muscle activation and fascicle dynamics in the MG and LG. We observed a higher normalized activation in the MG than in the LG during stance, which did not translate into greater MG normalized fascicle shortening. However, we observed significantly less normalized fascicle lengthening in the MG than in the LG during early stance, which matched with the timing of differences in activation between muscles. This resulted in more isometric behavior of the MG, which likely influences the muscle–tendon interaction and enhances the catapult-like mechanism in the MG compared with the LG. Nevertheless, this interplay between muscle activation and fascicle behavior, evident at the group level, was not observed at the individual level, as revealed by the lack of correlation between the MG–LG differences in activation and MG–LG differences in fascicle behavior. The MG and LG are often considered as equivalent muscles but the neuromechanical differences between them suggest that they may have distinct functional roles during locomotion.
Fichier principal
Vignette du fichier
jeb242626.pdf (542.58 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-03297170 , version 1 (20-06-2023)

Identifiants

Citer

Raphaël Hamard, Jeroen Aeles, Nicole Kelp, Romain Feigean, François Hug, et al.. Does different activation between the medial and the lateral gastrocnemius during walking translate into different fascicle behavior?. Journal of Experimental Biology, 2021, 224 (12), pp.jeb242626. ⟨10.1242/jeb.242626⟩. ⟨hal-03297170⟩
71 Consultations
7 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More